Multipoint Accessory Rail for Composite-Frame Pistol

ABSTRACT

Accessory mounting rails having locating and clamping elements can be secured to the lower frame of a composite-framed pistol with uniform clamping force to prevent distortion of the lower frame and improve firearm operational reliability. Standard or custom accessory-mounting features may be provided in one or more locations above, below, and to the right and left sides of the pistol&#39;s barrel, allowing a number of accessories to be installed and operated together.

CONTINUITY AND CLAIM OF PRIORITY

This is an original U.S. patent application.

FIELD

The invention relates to firearm accessories. More specifically, the invention relates to adapters to mount accessories to a composite-frame semiautomatic pistol.

BACKGROUND

Firearms such as pistols and rifles are often fitted with accessories to improve their handling, accuracy, or overall ease of use. Telescopes (“scopes”) for obtaining clearer images of targets, lasers for projecting indicators onto a target, and flashlights for illuminating the area in front of the firearm, are examples of such accessories. Several standard mounting systems have been developed to permit arbitrary equipment to be securely attached to a firearm, and adapters are available to permit an accessory having one mounting to be attached to a firearm via a different mounting.

FIG. 19 shows a segment of “Picatinny” rail: a common, standardized mounting interface. A Picatinny rail 1910 is a length of rigid material having a predefined cross-section 1920 and uniformly-spaced transverse grooves or channels, as seen in side view 1930, circled at 1940. An accessory mounts to Picatinny rail via a base or shoe (FIG. 20, 2010 ) having a complementary channel (see FIG. 20 , channel 2020). The accessory can slide along the rail or be secured in place via a locating pin that passes through one of the grooves in the rail or a set screw driven against the side of the rail. Other mounting systems, such as Weaver rail, have differently-shaped rails or different securing mechanisms, but the general concept is similar.

Although accessories increase the weight and size of a firearm, some are so useful or convenient that even users of smaller firearms such as pistols decide to attach them to their weapons. And consequently, pistol manufacturers have provided structural features that permit the attachment of such devices.

However, certain operational characteristics of a pistol (e.g. the reciprocating motion of the slide of a semi-automatic pistol) and certain materials used in the construction of some pistols (e.g. the composite frame of some lightweight handguns) complicate the secure attachment of accessories. Structures and techniques to improve the robustness of the accessory/firearm interface may be of value in this field.

SUMMARY

An accessory mount having a clamp structure and a cage structure may be secured to the lower frame of a pistol, including a composite-framed pistol, with a plurality of clamping elements so that the clamping force is distributed evenly along the clamp interface. Accessory mounting structures such as Picatinny or Weaver rails are provided to secure accessories adjacent, and aligned with, the barrel of the pistol. Accessory mounts according to embodiments of the invention may be made from suitably shaped aluminum extrusion.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an embodiment of the invention secured below the barrel of a semi-automatic pistol.

FIG. 2 shows the embodiment of FIG. 1 from another viewpoint.

FIG. 3 shows another view of an embodiment of the invention secured below the barrel of a semi-automatic pistol.

FIG. 4 shows the parts of FIG. 3 in a different relationship to one another.

FIG. 5 shows the parts of FIG. 3 moved differently to expose other characteristics.

FIG. 6 shows another embodiment of the invention.

FIG. 7 is a perspective view of an embodiment of the invention. FIGS. 8-12 are right, front, rear, top and bottom views thereof.

FIG. 13 is a perspective view of an embodiment of the invention. FIGS. 14-18 are left, front, rear, top and bottom views thereof.

FIG. 19 shows a length of Picatinny rail.

FIG. 20 shows a portion of an accessory that can mount to Picatinny rail.

DETAILED DESCRIPTION

An embodiment of the invention is a mounting accessory or adapter for a pistol or handgun. It is secured to a frame of the handgun below the barrel and ahead of the trigger mechanism, and forms a cage around the barrel, outside the reciprocating slide mechanism. Accessory mounting features are provided at least above (and aligned with) the barrel. Some embodiments provide additional mounting features below the barrel and adjacent one or both sides thereof.

FIG. 1 shows an embodiment of the invention, generally 100, secured to a semiautomatic pistol 190 by a mounting structure, generally near 110. An upper portion of the embodiment 120, above and aligned with the barrel, provides a standard accessory mounting structure such as Picatinny-compatible rail. The reciprocating action or slide of the handgun is identified at 190; it moves back and forth during use as indicated at 195.

FIG. 2 shows the embodiment 100 and handgun 180 of FIG. 1 from a different viewpoint. Here, it is apparent that the embodiment forms a cage around the slide 190, as indicated by dashed lines 270. The barrel of the firearm is marked at 290.

FIG. 3 shows the same embodiment 100 and handgun from earlier Figures, from a front view. The embodiment 100 clears the entire slide as shown by dashed line 370. The embodiment is secured to the lower frame of the handgun 350 near a mounting interface indicated at 360.

In FIG. 4 , the embodiment 100 has been displaced horizontally from the firearm. This view shows that an embodiment may have a gap at 410 between the left and right sides of the cage; one or more threaded fasteners passing across the gap near 430 can pull the right and left halves together and exert a pinching force between protrusions 420. These protrusions have a complementary shape to enter channels in the lower frame of the handgun near arrows 460, and when the fastener(s) are tightened, the embodiment is clamped and secured to the handgun. From this viewpoint, one can see that the front profile of the embodiment is somewhat similar to a Greek Omega (Q) character, 480. The loop of the Q, crosshatched at 482, corresponds to the upper portion of the cage, while the clamping portion near 430 corresponds to the tails or “swashes” of the Q character, dotted fill at 484 and 486.

FIG. 4 also shows that the upper extent of the cage is formed in a dovetail or keystone shape, 470. This shape allows accessories to be mounted to the embodiment above the barrel. The lower clamping portion may also form a dovetail or keystone shape, which may be provided with transverse notches or other features so that it, too, allows accessories to be mounted to the embodiment (below the barrel).

It is appreciated that a structure having this Omega shape may be manufactured efficiently from a length of extruded material such as steel or (preferably) aluminum. The extrusion may comprise all of the shapes shown: the pinching points 420, interior surface near (but not interfering with) the reciprocating slide, the outer surface, and the dovetail or keystone shapes at top and bottom. A segment of such extrusion may be machined transverse to its length to create the overall side profile, notches in the mounting rails, openings for transverse fasteners, and skeletonization for appearance and weight reduction. Aluminum can be treated with an anodization process to imbue the surface of an embodiment with a desired color and a tough finish.

FIG. 5 shows a right side view of the handgun 180 and embodiment 100, where the embodiment has been displaced vertically from its normal location. Openings in the lower extent of the embodiment, identified at 510 and 520, permit locating or clamping elements, such as threaded fasteners, to pass transversely through the embodiment from right to left and to clamp the right and left sides of the embodiment cage together, as described earlier.

Note that the openings 510 and 520 are displaced vertically along the length of the clamping portion of the embodiment that resides under the barrel of the firearm. Thus, the element through opening 510 passes through a notch in the frame of the handgun, 585. The element, which is indicated at 515, serves a locating function, with its position in notch 585 preventing the embodiment from sliding forward or backward under the barrel of the firearm by interfering with the lower frame when such motion is attempted.

In contrast to the element through opening 510, the element through opening 520 passes completely below the frame of the handgun, as shown at 525. Thus, this element only provides a clamping function, without interfering with fore/aft motion as the locating element does.

It is appreciated that there is a limited length of the firearm frame below the barrel and ahead of the trigger mechanism. Prior-art attachment mechanisms used only a single fastener to perform both clamping and positioning functions. However, particularly for firearms with a composite (rather than metal) lower frame, a single clamping force exerted in this location can cause slight distortion of the frame, which increases the chance of misfeed or other malfunction. Positioning a plurality of fasteners along the interface between the firearm and the accessory mount, with at least one fastener providing a locating function and at least one other fastener providing only a clamping function, distributes the securing force more evenly and results in a strong, immobile joint with less overall clamping force required. This, in turn, reduces the distortion of a non-rigid (e.g. composite) frame, and improves operational reliability.

FIG. 6 shows another embodiment of the invention 600, suitable for a handgun with a longer barrel. The embodiment has a correspondingly longer accessory attachment area 610. There are three (rather than two) securing openings, at 620, 630 and 640, but their locations are displaced vertically from each other. Openings 620 and 630 guide clamping fasteners below the frame of the firearm, while opening 640 allows a positioning element to pass through a locating notch in the frame, in similar fashion to element 515 and opening 510 in the embodiment shown in FIG. 5 . Since there are a plurality of separate clamping elements, the positioning element at 640 may provide no clamping force whatsoever, and may serve only a locating function—the multiple clamps allow the total clamping force to be distributed more evenly as compared to an accessory mount with only a single clamp.

FIG. 6 also shows how an embodiment may provide additional accessory-mounting locations. Here, openings at 652 and 654 in the left side of the cage; and 656 and 658 in the right side of the cage, may be tapped to accept screw-in accessories directly, or a length of accessory mounting rail such as that shown in FIG. 19 may be secured at these holes. Accessory rails attached to the right and left sides of the cage are also aligned with the barrel, and may be used to secure laser targeting devices, flashlights, or other accessories.

FIG. 7 is an isometric view of an embodiment like that discussed in FIGS. 1-5 . FIGS. 8-12 show right, front, rear, top and bottom views thereof, respectively. Note that both the top and bottom of the embodiment comprises a dovetail or keystone profile, so firearm accessories can be attached both above and below the barrel. An embodiment may offer different attachment rail profiles on the top and bottom surfaces (e.g., Picatinny on the top and Weaver on the bottom), or the attachment facilities may simply comprise mounting holes for lengths of accessory rail suitable for the user's needs, as described with reference to the left and right sides of FIG. 6 .

FIG. 13 is an isometric view of a longer embodiment similar to that discussed with reference to FIG. 6 . FIGS. 14-18 are left, front, rear, top and bottom views thereof. Note that the three openings shown in the left view of FIG. 14 are not horizontally aligned—one opening is higher (closer to the barrel) than the others, so that an element therethrough can perform a fore/aft locating function by passing through a notch or similar feature in the frame of the pistol below the barrel and interfering with the frame when it is attempted to slide the embodiment along the mounting interface.

The structures and characteristics of the present invention have been described largely by reference to specific examples and in terms of particular arrangements of features. However, those of skill in the art will recognize that a firearm accessory mount can also be structured somewhat differently than herein described, while retaining the uniform clamping force, fore/aft location fixing, and reduced distortion of a non-rigid firearm frame, by structures that are visually different from those depicted here. Such variations and visually-different structures are understood to be captured according to the following claims. 

We claim:
 1. An accessory mount for a pistol, comprising: a clamp structure adapted to interface with a lower frame of a pistol below a barrel of the pistol; a cage structure coupled to the clamp structure and configured to surround a slide of the pistol, said cage sized and shaped to permit the slide of the pistol to reciprocate without interference from the cage; at least one locating element extending from a left side of the clamp structure to a right side of the clamp structure, said at least one locating element functional to prevent the accessory mount from sliding forward or backward along the lower frame by interfering with a feature of the lower frame; a clamping fastener extending from the left side of the clamp structure to the right side of the clamp structure, said clamping fastener functional to urge the left side of the clamp structure towards the right side of the clamp structure and to pinch the lower frame without ability to prevent the accessory mount from sliding forward or backward along the lower frame by interfering with a feature of the lower frame; and a plurality of accessory-mounting structures coupled to the clamp structure and the cage structure, each accessory-mounting structure of said plurality of accessory-mounting structures adapted to secure at least one accessory to the pistol.
 2. The accessory mount of claim 1 wherein the locating element is functional to urge the left side of the clamp structure towards the right side of the clamp structure and to pinch the lower frame, and wherein the locating element and the clamping fastener together distribute a total clamping force evenly along the clamp structure.
 3. The accessory mount of claim 1 wherein the clamping fastener is a first clamping fastener, the accessory mount further comprising: a second clamping fastener extending from the left side of the clamp structure to the right side of the clamp structure, said second clamping fastener functional to urge the left side of the clamp structure toward the right side of the clamp structure and to pinch the lower frame without ability to prevent the accessory mount from sliding forward or backward along the lower frame by interfering with a feature of the lower frame, wherein said first clamping fastener and second clamping fastener together distribute a total clamping force evenly along the clamp structure.
 4. The accessory mount of claim 1 wherein each accessory-mounting structure of the plurality of accessory-mounting structures is configured to secure accessories adapted to mount to a standard mounting rail chosen from the group consisting of a Picatinny rail and a Weaver rail.
 5. The accessory mount of claim 1 wherein a first accessory-mounting structure of the plurality of accessory-mounting structures is configured to secure accessories adapted to mount to a first standard mounting rail, and a second accessory-mounting structure of the plurality of accessory-mounting structures is configured to secure accessories adapted to mount to the standard mounting rail.
 6. The accessory mount of claim 1 wherein a first accessory-mounting structure of the plurality of accessory-mounting structures is configured to secure accessories adapted to mount to a first standard mounting rail, and a second accessory-mounting structure of the plurality of accessory-mounting structures is configured to secure accessories adapted to mount to a second, different standard mounting rail.
 7. An accessory mount for a pistol, comprising: a cage structure having a shape similar to a Greek letter Omega (Q) when viewed from a front, said cage structure having an upper loop shaped to surround a slide of the pistol without interfering with a reciprocating motion of the slide of the pistol, said cage structure having a lower clamp shaped to mate securely with a lower frame of the pistol below a barrel of the pistol; the lower clamp having a plurality of openings to accept a corresponding plurality of fasteners traveling from a left side of the pistol to a right side of the pistol, transverse to and below a barrel of the pistol; a first length of a standard accessory mounting rail coupled to the cage structure and aligned with the barrel of the pistol; and a second length of a standard accessory mounting rail coupled to the lower clamp below the barrel of the pistol and aligned therewith.
 8. The accessory mount of claim 4 wherein the plurality of openings is two openings.
 9. The accessory mount of claim 8 wherein a positioning fastener passing through the first opening of the two openings passes adjacent the lower frame of the pistol at a location where the positioning fastener prevents the accessory mount from moving forward or backward on the lower frame by interfering with the lower frame.
 10. The accessory mount of claim 8 wherein a clamping fastener passing through the second opening of the two openings passes adjacent the lower frame of the pistol at a location where the clamping fastener does not interfere with the lower frame as the accessory mount is moved forward or backward on the lower frame.
 11. The accessory mount of claim 4 wherein the first length of the standard accessory mounting rail is a Picatinny rail.
 12. The accessory mount of claim 4 wherein the second length of the standard accessory mounting rail is a Picatinny rail.
 13. The accessory mount of claim 4 wherein the first length of the standard accessory mounting rail is a different shape than the second length of the standard accessory mounting rail.
 14. An accessory mount for a pistol comprising: a segment of extruded channel having an Omega (‘Ω’) profile and a length; a loop of the extruded channel sized to surround a slide of a pistol and allow the slide to reciprocate without interference; a shape of the extruded channel between swashes of the Omega profile adapted to complement a shape of a lower frame of the pistol below the barrel and forward of a trigger assembly, said segment of extruded channel shaped transversely to its length to form a shaped structure, wherein a side profile of the shaped structure comprises a first opening for a locating element to pass from one side of the extruded channel to another side of the extruded channel, said locating element positioned to interfere with the lower frame of the pistol and prevent the shaped structure from sliding along the lower frame; a second opening for a clamping element to pass from the one side of the extruded channel to the another side of the extruded channel, said clamping element positioned not to interfere with the lower frame of the pistol when the shaped structure slides along the lower frame; a first length of a standard accessory mounting rail at an upper extreme of the Omega profile and aligned with the barrel; and a second length of a standard accessory mounting rail at a lower extreme of the Omega profile and aligned with the barrel.
 15. The accessory mount of claim 14 wherein the first length of the standard accessory rail is longer than the second length of the standard accessory rail.
 16. The accessory mount of claim 14 wherein a side of the shaped structure comprises a plurality of openings for attaching an accessory to the side of the shaped structure.
 17. The accessory mount of claim 14 wherein a side of the shaped structure comprises a plurality of openings for attaching a length of standard accessory rail to the side of the shaped structure.
 18. The accessory mount of claim 14 wherein a side of the shaped structure comprises a skeletonizing opening.
 19. The accessory mount of claim 14 wherein the extruded channel is formed of aluminum.
 20. The accessory mount of claim 18 wherein the extruded channel is treated with an anodized surface finish. 